Syringe.



F. S. DICKINSON.

SYRINGE.

APPLICATION 4PILEDOQT. 27, 1914.

1,130,493. Patented Manz, 1915.

clear,

OFFICE;

FAIRLEIGH S. DICKINSON, OF I'LUTHERFORD, NEW J RS-Y.

SYRINGE.

Specification of Letters Patent.

Patented Mar. 2, 1915.

Application filed October 27, 1914. Serial No. 868,812.

T0 all whom it may concern.'

Be it known that I, FAIRLEIGH S. DICKIN- son, a citizen of.. the United States, and a resident of Rutherford, in the county of Bergen and State of New Jersey, have invented new and usefull Improvements in Syringes, of which the following is a full,

and exact description.

The object of the invention is to provide certain new and useful improvements'in syringes and like devices whereby the plunger is held against accidental dropping out of the barrel.

In order to accomplish the desired result, use is made of a combined nger piece and plunger retainer, of which the finger piece is held on the barrel and the plunger retainer is in the form of a coil spring attached at its ends to the ringer piece and engaging the outer surface of the plunger so as to hold the latter against accidental dropping out of the barrel. l

A practical embodiment of the invention is represented in the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a side elevation of an ordinary syringe provided with the combined finger piece and retaining device; Fig. 2 is a cross section of the same on the line 2-2 of Fig. 1; and Fig. 3 is a perspective View of the combined finger piece and retaining device. In syringes, especially those made of glass, as now generally constructed, the plunger is liable to drop out of the barrel when pointing the nozzle thereof in an upward drection and hence the plunger is liable to be broken, injured or soiled, so as to render the syringe unfit for use. In order to prevent the plunger from accidentally dropping out of the barrel, use is made of a retaining device presently to be described in detail.

The syringe shown in Figs. l and 2 consists of the usual barrel A in which reciprocates a piston B provided at its outer end with a suitable handle B. The barrel A is provided at its outer end with the usual discharge nozzle A and at the rear end with a flange A2 against which rests a ring C encircling the barrel A and provided with outwardly extending finger pieces D adapted to be taken hold of by the user of the syringe when actuating the plunger B in the barrel A for ejecting the liquid contained in the barrel. On the .finger pieces D are held loops E to which are secured the ends of a coil spring F which normally extends diametrically across the ring C but is adapted tb be deflected sidewise when inserting the plunger B into the barrel A so that the sprlng F is placed under tension and bears against the outer surface of the plunger B with sufficient force to hold the plunger against accidental movement or dropping out of the barrel A when holding the syringe with the nozzle A pointing upward, as indicated in Fig. 1. It is understood that the spring F does not interfere with the operator reciprocating the plunger B in the barrel A for drawing in the liquid or ejecting the same in the usual manner, but the spring F on account of being under tension and encircling a portion of the plunger B holds the latter against accidental movement as previously explained.

The finger piece and retaining device shown and described is very simple in construction and can be readily placed in position on the syringe for the purpose men-4 tioned.

When using the syringe for ejecting a fluid contained in the barrel A, the operator engages the finger pieces D with the forefinger' and athe middle finger, and with the thumb presses the plunger B inward to eject the fluid through the nozzle A.

Having thusdescribed my invention, I claim as new and desire to secure by Letters Patent:

1. A syringe attachment, comprising a coilspring adapted to bear on the plunger adjacent the rear end of the barrel to hold the plunger against accidental movement in the barrel, and a support adapted to engage the rear end of the barrel and to which the ends of the suspended coil spring are to be placed under tension by the syringe plunger' to bear on the latter.

3. A syringe attachment, comprising a ring adapted to engage the barrel of the end thereof, finger pieces loops held on the said syringe at the rear on the said ring,

nger pieces and bearing against the said ring, and a coil springattached'at its ends to the said loops to normally extend diametrcally across the ring, the said spring being adapted to be deflected and placed under tenslon by the syringe plunger to bear on the surface thereof.

Lmoglos ln testimony whereof l have signed my name to this specicaton in the presence of two subscribing Witnesses.

FAIRLEGH S. DICKINSON.

`l/Vtnesses:

THEO. G. Hos'mn, M, ROBIN. 

